condition mean min max ZT0-3 1.9 1.9 1.9 ZT4-7 2.6 2.6 2.6 ZT8-11 8.25 8.25 8.25 ZT12-15 32.05 32.05 32.05 ZT16-19 7.8 7.8 7.8 ZT20-23 9.25 9.25 9.25